腔内反射增强技术可有效提高紫外激光四倍频效率,但反射增强腔存在多次反射光斑不重合、光束发散角不一致的问题。为了获得更好的光束质量, 设计了一种实现多次反射绿光光束可重现的反射腔结构, 采用传输矩阵法计算了反射光束及四倍频转换等参量。结果表明, 可重现的反射腔不仅能有效避免反射增强腔内光束半径不一致导致的光束质量差的问题, 还可进一步提升四倍频效率。

Reflective enhancement has been proved to be an efficient way to raise the transfer efficiency of 266nm laser generation by the fourth harmonic generation (FHG). However, the reported enhancement cavities have some disadvantages, such as, the light beams reflected by different times are not overlapped well and the beam quality of violet light is poor. In order to obtain better beam quality, a new reflective cavity was described to realize the well overlap of the beams reflected by different times. The beam profile and transfer efficiency were calculated. The results show that a good beam quality of FHG violet light can be achieved and the efficiency of FHG can be further improved.